FR2471715A1 - DEVICE FOR RECORDING ON A DISC SOUNDS AND IMAGES IN THE FORM OF ELECTRICAL SIGNALS - Google Patents

Abstract

THE DEVICE INCLUDES A MEMORY OF 3 LINES FOR SOUND AND IMAGE IN WHICH CAN BE EMAGANIZED LINE BY LINE AND IN THE FORM OF ELECTRIC PULSES THE INFORMATION OF SOUND AND IMAGE, A LASER 7 WHOSE BEAM 8 IS CONDUCTED THROUGH A MODULATOR 10, A MOBILE DEVIATION DEVICE 15 BY WHICH THE LASER BEAM 12 MODULATES AND FOCUSED BY A LENS 16 CAN BE RETURNED ON A PHOTOSENSITIVE LAYER 21 COVERING A VIDEO DISK 20 AS WELL AS A TURNTABLE 19 WHICH IS MOUNTED ON A TROLLEY 22.

Description

The present invention relates, on the one hand, to a device for

  recording video information as half-tone images in the form of electrical signals which are successively arranged on a spiral extending around the center of a video disc and are related part, to the recording of sounds in the form of electrical signals and associated with the images by forming an optical sound track alongside the half-tone images as well as control tracks regulating the playback of the disc and also associated with the

spiral halftone images.

The electrical input signals of sound and ima-

  ges applied to the device may for example be output signals from a cinematographic film player,

  a video camera, a television receiver, a player

  tape or similar device allows

  so much to convert recorded information into electrical signals. A device of this type is used for manufacturing video discs or for producing a disc array

  video that can be played by a reproduction device.

A reading device is known which makes it possible to produce a video disc having a row of half-tone images arranged in the form of a spiral, by projecting

  the images on a photosensitive layer covering the disc.

In this method, a strip-like film having a series of halftone images, for example moving images, which is used continuously and synchronously with the rotation of the video disc in a projection device with a slit diaphragm (DE-OS 2 427 428). When we then want to reproduce also the sound and control information for the

  adjustment of the rotation of the disc to be manufactured, this information

  These must already appear on the film to be copied in the places corresponding to those provided on the disc, or they must be copied separately. In this case we are not only faced with difficulties with regard to the precise synchronization of sound and images but it is also necessary to provide special devices.

  for separate exposure of the photosensitive layer of the device

  than. The object of the present invention is to simplify the

  method of manufacturing a video disc in a single operation

  tion by means of a single device and according to which are pre-

seen on the upper side of the video disc coated with a

  a photosensitive row of halftone images in a spiral pattern and next to it and associated with the images one or more sound tracks, a control track for adjusting the

disc read speed, a control track for eli-

  undermining unwanted disc movements or oscillations

  in the plane of the photosensitive layer and a track

to eliminate movements of the disc in the plane

  perpendicular to the photosensitive layer, the signals from

  being formed by electrical impulses and the image, sound and control signals which may come from

different pulse generators.

  The designation "photosensitive layer" refers

not only to a layer in which the light exposure

  neuse creates the desired halftone blackening but also a layer in which occurs during

  the exposure of more or less pro-

  backgrounds depending on the light intensity.

  These problems are solved in accordance with the invention by a device which is characterized by: 1. a line memory for sound and image RAM in which can be stored line after line,

  according to a desired succession and after analog conversion-

  digital, the electrical impulses constituting the information

  image and sound information as well as information

mations for the realization of order tracks from

  of a constant value ROM.

2. A laser whose light beam is led to

through a modulator in order to modulate the pre-

  line memory throws for sound and RAM image

  after a digital-to-analog conversion.

  3. A mobile deflection device by means of which the modulated and focused laser beam by an objective can be returned on the photoresponsive layer and be guided along a line during the recording.

  4. A turntable which is mounted for tour-

  ner on a trolley movable in the plane of the turntable

  disc and which removably carries a coated video disc

a photosensitive layer on which the beam is directed

light beam after focusing by the lens in order to

  record line by line information from the

line memory for sound and image RAM.

  The modulation device can be a modulator

  electro-optic or electro-acoustic, the device for

  see a swiveling mirror, a rotating prism or a

rotating mirror wheel.

The device according to the invention presents the advantage

  that the video disc can be recorded

at relatively high speed and that the half images

tones can be created not only by blackening

  of the photosensitive layer but also by an evaporator

  tion of matter. This evaporation creates a ma-

negative trice which can be used to make transparent disc coatings with a gray tint or transparent coatings whose recesses can

be filled with a transparent material added with pig-

gray tones.

  Various other features of the invention res-

  emerge from the detailed description which follows.

Embodiments of the subject of the invention are shown, by way of nonlimiting examples, in

attached drawings.

  Fig. 1 is a schematic representation of the dis-

positive according to the invention.

Fig. 2a shows an additional device to the

  positive according to Figure 1 using a mirror wheel.

  Fig. 2b represents the same device as the

2471711 5

Figure 2a but the mirror wheel is in another position. Fig. 3 shows the additional device of

  Figures 2a and 2b but using the objective of a micros-

  cope. Image information read line by line using a reader from a halftone image or an information storage disc or magnetic tape is applied to input 1 under

  successive electrical pulses and this information

  tions are introduced in the form of digital signals into a line memory for sound and image RAM 3 by

  through an analog-to-digital converter 2.

  Alternating to the image information of the informa-

  sound are also applied as an impulse

  successive electrical sions at input 4 and are intro-

  picks in line memory for sound and picture 3

  via a second analog converter

numeric 5. The reference 6-designates a ROM read-only memory which transmits synchronously to the line memory for

  sound and image 3 the information intended for the realization

tion of constant command tracks. These tracks of com-

mande are identical for each of the discs described and

consist for example of a re -.- control track

  sliding the scrolling speed and appearing under the

form of a sinusoidal curve whose frequency varies

continuously and by control tracks eliminating the

disc oscillations and in the form of a

  straight genes. The different information groups mentioned-

born above are stored successively and in the form of a linear row in the memory of lines 3 for sound and image and therefore these groups of information are associated with one of the lines of the image to reproduce and this in the order in which they must be recorded line after line on the disc. Consequently the memory of lines 3 represents each time a line of the total image to be reproduced on the video disc and this line is composed of sections of the halftone image which can be subdivided into different colored prints and of sections provided for the sound information and the different

control tracks.

A light beam 8 emitted by a laser 7 is di-

rigé, after having been made parallel by a condenser not shown, on a mirror 9 which returns the beam

on an electro-optical or electro-acoustic modulator 10.

  The signals delivered line after line by the RAM memory 3, and carried by the light beam 8, are modulated by

the modulator 10 after their transformation in the conver-

  digital-analog weaver-11. The light beam mo-

  dulé 12 coming from the modulator 10 is directed by a mirror 13 on a deflection device 14 which can be an oscillating mirror whose movement per unit of time corresponds to the recording of a line and which returns to its initial position with each change line. The oscillating mirror 14 can be controlled by a piezoelectric device 15 so that it conducts the modulated light beam 12 along a line of the image during recording. After having been deflected by the mirror 14, the light beam 12 is first focused by a lens 16 and straightened, to

be parallel, by a condenser 17 so that each if-

general to save is in the form of a point. A lens 18, the axis of which is perpendicular to the line to be recorded, can be placed in the path of the beam from the condenser 17 in order to widen the line. A turntable 19, on which is placed

  removably a video disc 20 coated with a photo layer

sensitive 21, is arranged perpendicularly below the light beam 12 coming from the condenser 17 so that the line to be recorded extends radially with respect to the video disc 20. The turntable 19 is mounted on a carriage 22 which can be moved in the sense of

line to be recorded by a linear motor 23. Another mo-

linear tor 24 acting on the periphery of the plateau

record player 19 controls the rotation thereof.

A spiral on which the recorded lines are arranged radially is created around the center of the

video disc 20 thanks to the movements resulting from the

born of the two linear motors 23 and 24. An electronic device with a program not shown, and controlling the linear motor 23 intended for the movement of the carriage 22, makes it possible to adjust and modify the pitch of the spiral. Another electronic control, also not shown, of the

linear motor 24 makes it possible to vary the speed of ro-

  the turntable during recording so that the angular speed remains constant at the location

of the impact of the beam 12 in order to always obtain ima-

ages of the same size.

  The oscillating mirror 15 shown in Figure 1 is

  always moves at an angle of 450 relative to the beam

incident light beam 12. This beam is deflected by 900 and moved in parallel by the mirror 15 in order to write a line at each oscillation of the latter. During the return movement of the oscillating mirror 15 the beam 12 must be interrupted. It is possible to remedy this drawback by replacing the oscillating mirror with a rotating prism or a mirror wheel which must be small and have a large number of facets. The passage of each angle of the mirror wheel or of the prism however creates an undesirable scattering light and the light beam

  12 is divided into two bundles of different directions.

  It would therefore also be necessary to interrupt the

  at each pass of an angle until the section

  total transverse strikes the next facet. In order to avoid

ter also this slight waste of time the invention pre-

  sees the return device shown in Figures 2a and 2b. In this embodiment, the mirror wheel 25 returns by each of its facets the light beam 12, coming from the modulator 10 and the deflection mirror 13, onto the photosensitive layer 21 and makes the beam rotate along the line to be recorded. Reference 26 designates a polarization switch and reference 27 indicates a crystal

2 471 71 5

  of limestone carbonate. Between the carbonate crystal cal-

  27 and the mirror wheel 25 is arranged a beam splitter 28 which forms an angle of 450 with respect to the axis of the incident light beam 12. A lens 29 focusing the light beam on the photosensitive layer 21 is provided behind the beam splitter 28 and on the way

  rays reflected by the mirror wheel 25. This arrangement

tif eliminates the incidence of the passing angle of the mirror wheel 25 by deflecting the light beam

  12 in the limestone carbonate crystal 27.

  In FIG. 2a the deflected beam 12 ′ strikes the fac-

this 30 of the mirror wheel 25 and is reflected by this facet by the lens 29 and after a pivoting in the opposite direction to that of clockwise, on the point Z of the photosensitive layer, point which constitutes the

end of the line to be recorded which begins at point a. When-

  that the point Z is reached, the polarization switch 26 is actuated which has the effect that the beam 12, which is no longer deflected, is directed on the facet 32 by eliminating

the incidence of the angle of the mirrors, this beam being made

  seen by facet 32 on point a that is to say on the

start of a new line; meanwhile the turntable

disc 19 has rotated a line interval from the

point a from the previous line.

  As can be seen from FIG. 2b, the beam not

  deflected and reflected 12 was rotated during the subsequent rotation

quente of the mirror wheel 25 on the point X of the photosensitive layer, point which is in the middle of the line to be written. In this position of the mirror wheel 25, the

  facet 32 is parallel to the plane of the photosensitive layer

  ble 21 and beam 12 to reflect. Then the switching

polarization sensor is actuated again and therefore the beam 12, which is now deflected, is directed, in this position of the facet 32, exactly on the point X

so that the line recording is not uninformed

  overwhelmed. The deflected beam 12 'is then pivoted along the line until it reaches the position shown in Figure 2a. The polarization switch 26 is inverted automatically and synchronously at the end of each line delivered by the line memory 3 and,

when the light beam reaches point X, this in-

  version which can be controlled by read-only memory 6. Since the mirror wheel 25 rotates continuously and synchronously, recording can be carried out without

  be interrupted by the line change.

The device described above is used when

  wants to record at high speed requiring rotation

  Quick reaction of the mirror wheel. In this case it is not possible to use a device in which the light beam is guided intermittently, that is to say in which the beam must be interrupted when the return mirror returns to its position initial or during

  passage of the angles of the mirror wheel or of the prism.

  When you want to record images of a very small format whose surface is for example between

  1 and 2 mm2, which requires the use of a microsensor objective

copeon must use the device shown in figure 3.

  Due to the separate and parallel guidance of the beam 12 not deflected by the limestone carbonate crystal 27 and the

  beam 12 'deflected by the latter it would be necessary to

  use too large an aperture for the objective used for reproduction on the photosensitive layer 21. For this reason, the two beams 12 and 12 ′ must be brought together again

  before they get into that goal.

In this case an additional objective 34 having for example a focal distance of 90 mm is arranged following the objective 29 which has for example a distance

  35 mm focal length, the plane of the intermediate image being

  signed by 35. In the beam path coming from the ob-

jectif 34 is placed a second crystal of carbonate cal-

  caire 36 which makes it possible to reunite the bundle 12 'with the bundle 12 so that a single bundle 12 arrives

  to the microscope objective 37 which reproduces the signal

vré by the modulator 10 in the form of a point on the layer

photosensitive 21.

  The invention is not limited to the use of linear motors 23 and 24 because these motors can be replaced by stepper motors. It is also not going beyond the scope of the invention if the sound information is applied to input 1 and the image information to input 2

or vice versa instead of applying to successive entry i-

  sound and picture information.

Claims (8)

R E V E N D I C A T I O N S 1. Device for recording video information as half-tone images under form of electrical signals and which are arranged successively   sively on a spiral extending around the center of a video disc and recording sounds appearing under   form of electrical signals and associated with images in form   an optical sound track next to the halftone images   as well as control tracks regulating the playback of the that and also associated with the spiral of half images   tones, characterized by: 1. A line memory for sound and image RAM (3) in which can be stored line after   line, according to a desired succession and after conversion ana-   digital-logic, the electrical pulses constituting the image information and the sound information as well as the information for the realization of the control tracks from a constant value read-only memory (6).   2. A laser (7) whose light beam (8) is led through a modulator (10) in order to modulate the information taken from the line memory for the sound and the RAM image (3) after digital-to-analog conversion. 3. A mobile return device (15) by means from which the laser beam (12) modulated and focused by an object jectif (16) can be returned to the photosensitive layer   (21) and be guided along a line during the recording   is lying. 4. A turntable (19) which is mounted to rotate on a carriage (22) movable in the plane of the   turntable and which removably carries a   that video (20) coated with a photosensitive layer (21) on which is directed the light beam (12) after its focus   reading by the lens (19) in order to record line by line the information coming from the line memory for sound and image RAM (3).   2. Device according to claim 1, character-   laughed at in that the modulating device (10) is a electro-optical or electro-acoustic modulator. 3. Device according to one of claims 1   and 2, characterized in that the deflection or deflection device (15) is an oscillating mirror, a rotating wheel with mirrors or a rotating prism.   4. Device according to claim 3, character-   laughed at in that it comprises, when a wheel is present mirrors (25) in the beam path (12), a switching polarization sensor (26) placed between the modulator (10) and the mirror wheel (25), a switch which is followed by a birefringent crystal (27) after which is provided a ray divider plate (28) which forms a angle of 450 relative to the beam path (12) and through which the beam (12) can be deflected at a right angle and sent   on the facets (30, 32) of the mirror wheel (25), the -com polarization mutator (26) which can be reversed when the beam (12 ') deflected by the crystal (27) reaches one of the angles (31) of the mirror wheel (25) and when the   beam (12) deflected by crystal (27) is directed perpetually   specifically on one of the facets (32) of the mid-wheel blacks (25). 5. Device according to claim 4, characterized in that a second objective (24), which is followed by a second birefringent crystal (36) disposed in the path of the light beams (12, 12 ') reflected by the mirror wheel (25), is provided following a first objective (29) and in that a microscope objective (37) is arranged in the path of the light beam (12) between the second   birefringent crystal (36) and the photosensitive layer (21).   6. Device according to one of claims 1   to 5, characterized in that it comprises a linear motor   (23) for moving the carriage (22) and a second mo-   linear tor (24) for controlling the rotation of the turntable (19) as well as a control device for regulating the movement of the carriage (22) and the rotation of the record player (19). 7. Device according to one of claims 1 to 6, characterized in that a lens (18) whose axis is perpendicular to the direction of the lines, is arranged in the   path of the light beam (12) downstream of the condenser (17).   8. Device according to one of claims 1 to   7, characterized in that the photosensitive layer (21) is made of a material which can evaporate under the effect of the beam luminous (12).